From this morning's Wall Street Journal (page A1 in the print edition), a return to one of last year's hot debates:
Exactly how the U.S. has managed to load on so much debt without seeing its net payments rise remains something of a mystery. Even in the second quarter, the U.S., in effect, was paying only a 0.4% annualized interest rate on its net debt. "It's still quite a good deal," says Pierre-Olivier Gourinchas, an economics professor at the University of California, Berkeley.
In a recent paper, Harvard economists Ricardo Hausmann and Federico Sturzenegger went so far as to suggest that the U.S. might not be a net debtor at all. Instead, they surmised, the U.S. might actually have income-producing assets abroad, such as know-how transferred to foreign subsidiaries, that have evaded measurement -- assets they call "dark matter," after a similarly elusive quarry in physics. Mr. Sturzenegger says the latest data haven't changed his view.
Most economists, however, see a more prosaic explanation: Foreigners have been willing to accept a much lower return on relatively safe U.S. investments than U.S. investors have earned on their assets abroad. Take, for example, China, which since 2001 has invested some $250 billion in U.S. Treasury bonds yielding around 5% or less -- part of a strategy to boost its exports by keeping its currency cheap in relation to the dollar.
Well, to be fair to Hausmann and Sturzenegger, that interest rate differential was part of their story. Much of the debate was actually about the meaning of that differential: Is it some inherently superior aspect of the US economy that drives foreigners to pay a premium for our financial assets? Or is it the agenda of, for example, the People's Bank of China, pursuing policies that are more about internal political objectives than market fundamentals?
In any event, the Journal article suggests that, just maybe, we are seeing the beginning of the end:
As interest rates rise, America's debt payments are starting to climb -- so much so that for the first time in at least 90 years, the U.S. is paying noticeably more to its foreign creditors than it receives from its investments abroad. The gap reached $2.5 billion in the second quarter of 2006. In effect, the U.S. made a quarterly debt payment of about $22 for each American household, a turnaround from the $31 in net investment income per household it received a year earlier...
The gap is still small within the context of the $13 trillion American economy. And the trend could reverse if U.S. interest rates decline. But economists say America's emergence as a net payer illustrates an important point: In years to come, a growing share of whatever prosperity the nation achieves probably will be sent abroad in the form of debt-service payments. That means Americans will have to work harder to maintain the same living standards -- or cut back sharply to pay down the debt.
The article contains a lot of comments hinting at a deep instability that seem, to me, a bit over the top:
If the trend persists, it could also raise concerns about the nation's creditworthiness, putting pressure on the U.S. currency. "It's an additional challenge for the dollar," says Jim O'Neill, chief economist at Goldman Sachs in London...
Among economists' biggest concerns, though, is the fast pace at which the U.S. is accumulating new debt. As that leads to larger interest payments, it will make the current-account deficit harder to control -- a vicious cycle that could accelerate if worried foreign investors demand higher interest rates to compensate for the added risk...
"You end up having to pay more and borrow more," says the University of California's Prof. Gourinchas. "Things could get out of hand very quickly."
And this statement just seems wrong:
The size of the nation's debt payments matters because it represents a share of income that American consumers, companies and government won't be able to spend or save. The higher the debt payments, the harder it will be for the U.S. to prosper.
Any rapid change in capital flows could, of course, be disruptive in the short run, but a lot of borrowing by the country means the same thing as it does for you: Accumulated debt doesn't stop you from earning income, it just limits your ability to spend it. Nouriel Roubini puts his finger on what it all really means:
"Your standard of living is going to be reduced unless you work much harder," says Nouriel Roubini, chairman of Roubini Global Economics. "The longer we wait to adjust our consumption and reduce our debt, the bigger will be the impact on our consumption in the future."
No argument here.
UPDATE: You can find quite a few links to comments on dark matter at Alpha.Sources blog.